Traditionally, circuit-switched networks, such as the Public Switched Telephone Network (PSTN), support a vast majority of communications that are predominantly voice based. For security reasons, telephone calls over circuit-switched networks could be readily monitored using various wiretapping or monitoring technologies by law enforcement agencies when illicit communications were suspected.
As packet networks, such as the Internet, evolve, the amount of voice-over-packet (VoP) communications has exponentially increased. As VoP communications increase, the need for a way to monitor these communication sessions increases. Unfortunately, the ability to encrypt these communication sessions often renders techniques to monitor the communication sessions obsolete, especially given the increasing sophistication of encryption techniques. As such, criminals and terrorists are finding the Internet to be a safe harbor for interstate, national, and international communications, which include data transfers, file sharing, and application collaboration, in addition to voice communications. Once a communication is established through the packet networks and any available firewalls or other monitoring entities, encrypted communications containing illicit content will often go undetected. Many of the encryption techniques are virtually unbreakable, and the resources necessary to decrypt, monitor, and detect illicit communications are often impractical or unavailable. These security threats pose risks to individuals and enterprises, as well as states and nations. Accordingly, there is a need for a technique to prevent establishment of sessions that may be used for illicit communications, prior to the communication sessions being established.